Quantum Physics
Material losses in superconducting circuits fundamentally limit qubit coherence times and resonator quality factors. Most research efforts focus on mitigating losses at circuit interfaces, including metal--substrate, substrate--air, and…
The CNOT-complexity of an invertible matrix over $\mathbb{F}_2$ is the minimum number of CNOT gates needed to synthesize the corresponding linear reversible operator. While the maximum CNOT-complexity over all $n \times n$ matrices is known…
Conventional laser control schemes for cooling and gate operation of trapped ions are limited to the regime of weak laser intensities and small Lamb-Dicke parameters. To overcome this limitation, we present the concept of dark polarons:…
For pure two-qudit probes used in a single fixed setting to estimate a common SU(d) transformation, maximal total Fisher sensitivity and full local identifiability are mutually exclusive. We derive exact identities that determine the trace…
Molecular chirality plays a crucial role in physics, chemistry, life sciences and pharmacology. Nowadays, the chiral discrimination and control at the single-molecule level is urgently needed to reveal the origin of the chirality-relevant…
Capacitive loading has emerged as a major obstacle to scaling fluxonium qubits from one-dimensional to highly connected two-dimensional (2D) architectures, yet its physical origin remains poorly understood. We derive an analytical relation…
Recent demonstrations of quantum computational advantage have been driven largely by sampling problems. A prominent model, boson sampling, involves sampling from the output distribution of a linear optical network. However, its classical…
Classical general relativity allows time travel, but Hawking [Phys. Rev. D 46, 603 (1992)] conjectured that quantum mechanics ultimately prevents it. Here we propose a feasible experiment to test Hawking's Chronology Protection Conjecture…
Resonance states spatially diverge and are thus not square integrable. Instead, their norm is defined by the biorthogonal scalar product of left and right states. We replace the corresponding volume integral by a convenient boundary…
Rare-regime discovery in parameterized dynamical systems is an active-search problem: find one verified parameter at which a scientifically defined qualitative threshold is crossed, even when acceptable candidates are rare, nonconvex, or…
The transverse-field Ising model is a fundamental quantum spin system that captures the competition between quantum fluctuations and interactions, playing a central role in studies of quantum phase transitions and non-equilibrium dynamics.…
Although multi-label k-nearest neighbor (ML-kNN) is able to effectively solve multi-label learning (MLL) problem with local neighborhood similarity, its time complexity is nearly unacceptable with large-scale datasets. To solve this issue,…
High-dimensional qudit (i.e., $d$-level or $d$-state) systems outperform two-dimensional qubit (i.e., 2-level or 2-state) systems in some quantum information processing tasks. We exploit entanglement purification protocols (EPPs) for…
A quantum battery is a novel energy storage device that operates on the principles of quantum mechanics. To enhance the charging performance of quantum batteries and further provide theoretical support for their physical implementation, we…
Single-Photon Avalanche Diodes (SPADs) are critical components of emerging quantum communication networks that detect single photons. They are placed in satellites for long-distance communication and are susceptible to radiation-induced…
Photonic quantum sensing often uses low-rank entangled probes such as Greenberger-Horne-Zeilinger (GHZ), Bell, and NOON states. Although these probes are ideally rank-1, practical quantum state tomography (QST) can produce density-matrix…
We give, to our knowledge, the first plain-model, one-time information-theoretically secure, efficient unclonable encryption scheme for one classical bit. Previous work by Bhattacharyya and Culf (Nature Physics, 2026) and Bhattacharyya,…
The mean-field Heisenberg ferromagnet is a quantum spin model on the complete graph with isotropic spin-1/2 interactions. This non-commuting Hamiltonian is permutation and $\mathsf{SU}(2)$ invariant, and its Gibbs states undergo an…
Nonlinearity at the scale of zero-point motion opens new possibilities for the control and readout of nanomechanical systems, but achieving this remains a formidable challenge. Here we demonstrate that ultrastrong coupling (USC) between a…
In quantum systems, the contact with the environment is detrimental to the purity of the state, thus limiting the practical use of entangled sources in quantum information applications. This loss of purity is observed in the form of…